Since we don’t use Quasar’s build tools when using Quasar components with Laravel, we’ll need to modify Laravel Mix which is Laravel’s build tools. A quick google brought me to this article, perhaps you could give it a try? I will do when I have some spare time.

Your curly braces are out of place
In your call to total, you’re not supplying the parameters. Instead our total function won’t take any parameters and will instead use this.foo to get the value of foo.
You can’t use -foo to get the negative value of foo
<script>
export default {
data () {
return {
value1: 0,
value2: 0,
value3: 0,
computed: {
total: function(value1,value2,value3) {
return (value2*(value3/1200))/(1-Math.pow((1+value3/1200),(-value1)))
} } } } }
</script>